12" SW tracking dob - tracking problem

[nicks90]

Not entirely sure if this is the right section to post this in....

I have a 12" skywatcher dob with motorised tracking - the 'middle version' of the 12" truss tube dob that they no longer sell. Has tracking, but only a simple handset for RA and Dec and tracking.

It has a problem.

Just recently it hasnt been tracking. I follow the instructions to ensure the base is level, point the scope at polaris and then turn the power on and off twice and then back on again. From my understanding of the instructions, this tells the system what latitude its at and also where North is to enable it to track at the appropriate sidereal rate.

So far so good. All the buttons work and move the scope up down left right as it should - at all 3 speeds too. However when I select track, it doesnt seem to do anything. Jupiter wanders off etc in what seems like the same amount of time as if I dont select tracking.

So i took the cover off the side motor and base motor so I could have a look at the gubbins inside and had a test during daylight so I could see more clearly. You can see the slotted 'wheel' that travels in front of the encoders and when you select track, it spins up. So it does appear to be moving, but for whatever reason its not moving anywhere near fast enough.

I;ve tried using the mains adaptor to run it from the house 240v and also wiith my 12V battery, but it doesnt seem to make a difference.

can anyone give me any pointers as to what I should be looking at to get this sorted?

thanks

Nick

[Laurie61]

I don't own this scope so have no hands on knowledge but a couple of things to try if you haven't already is are the clutch's slipping and is it set for northern hemisphere ? 

[mitchelln]

One quick way to test the clutches is to move the mount with the buttons at slowest speed whilst holding the tube. If there is serious clutch slippage you won't feel the resistance to your hold.

[nicks90]

cheers for that pointer - i'll have a look at that this evening when I get home.

[nicks90]

Finally got around to taking a look at the tracking this morning.....shows how many clear nights we've had since I posted this :-(

Took both covers off the drives and both encoder wheels spin fine.

Tried to put some light resistance against the scope as it was tracking and could feel positive resistance and the motors ground to a halt under hard resistance - instead of slipping on too slack clutches.

Hmmmmmmmmmmmm puzzled.

So I set it going and left a plumb Bob in place to see how it moved over time.

ITS GOING THE WRONG WAY!!!!!!!

!doh!

So looks like its set to southern hemisphere. No idea how I've managed that and I can't find my destruction book to reset it. Does anyone happen to know bow to set it back to northern hemisphere?

Cheers muchly

Nick

[knobby]

[mitchelln]

Well, at least it looks like it's nothing serious!

Sent from my GT-N7105 using Tapatalk

[nicks90]

Mine isn't a syntrek handset, just a tracking dob. Need to check if it has a 'set' button, not sure...

Quick question, might I have the battery on the wrong way?

[knobby]

isn't the syntrek tracking and the sysnscan goto ?

[nicks90]

Ohhhh could be. Garage is all locked up and its pounding it down, so will have to have a look later on

[knobby]

Good luck 

[crashtestdummy]

Iirc it should be the syntrek Nick and it does have a set button.I never bothered with the tracking but the previous owner did so I would have thought ugh it would have been set to northern hemisphere .

[nicks90]

Confused. Pressing the set button and powering on makes no difference, still turns left on tracking. Tried it multiple times and its still going in the opposite direction...